1. Field of the Invention
The present invention relates to devices used to assess the penetrative performance characteristics of projectiles, and more particularly to such devices for simulating the anatomical features of game animals.
2. Description of Related Art
Big game hunting is an exhilarating sport enjoyed by many enthusiasts around the world. According to the 2001 National Survey of Fishing, Hunting and Wildlife-Related Recreation, there are approximately 11 million big game hunters in the United States that spend $6.5 billion on hunting related equipment annually. Big game is most often taken with rifles, although large caliber pistols, shotguns, and archery equipment are also commonly used. The best way to prepare for big game hunting and ensure one's success in bringing down these large animals is to know how the projectile, e.g. the bullet or arrow, will perform when shooting the intended game animal.
There are a wide variety of shooting targets and ballistic methodologies used to test projectile performance. Some of the more popular targets are wet pack (water soaked newspaper), ballistic gelatin, water filled tanks, and metal sheets. All of these shooting targets are deficient for various reasons when trying to accurately simulate a projectile's damage on a living animal. A common shortcoming with each target is the lack of a full “shoulder to shoulder” representation.
Specifically, none of these existing targets comprise a heterogeneous stacked mixture of materials having properties similar to their biologic counterparts, leaving the hunter with insufficient knowledge of how the projectiles would perform on a live animal. Animals are composed of hide, muscle, bone, and internal organs. All of these tissues must be accounted for to accurately predict projectile performance using a mechanical model.
Shooting enthusiasts are often limited in the resources they can devote to effectively testing projectile incapacitation on game animals. Therefore, cost effective devices and methods are of great interest to these hunters. However, inexpensive devices generally fail to deliver the reliable simulation results required, because their simple structures do not provide accurate analogs to anatomical tissues. Moreover, a projectile's mechanical behavior varies significantly with respect to its penetrating medium. For example, modeling a 30-inch wide Cape buffalo by using only thirty inches (30″) of ballistic gelatin will not provide the user an accurate simulation of real life bullet performance. Since the gelatin block does not incorporate a bone simulant, the bullet's expansion, deceleration, and fragmentation results cannot be regarded as reliable. Many people continue to use these homogeneous targets strictly because better alternatives do not exist. Therefore, prediction of projectile performance on a live animal remains speculative, calling into question the use of such unreliable methods from the start.
U.S. Pat. No. 7,222,525 to Jones discloses a device for testing bullet penetration, however, it does not provide a means for keeping the gelatin block from moving after impact from the bullet. Furthermore, the device does not account for the effect of hide, bone, or internal organs on the projectile. Importantly, ballistic gelatin can only be used to simulate muscle, not internal organs. The specific gravity and mechanical properties of muscle are different than internal organs, because internal organs contain more liquid and gases.
U.S. Pat. No. 523,510 to Brunswig discloses a tank system to measure projectile penetration. Similar to most other penetration testing devices, that invention does not take into account the effect of bone or hide on the projectile's performance.
U.S. Pat. No. 5,850,033 to Mirzeabasov, et al., most closely replicates one half of a torso of a human. However, even if this device were employed, one could not predict the effect of a shoulder-to-shoulder shot on a big game animal. In order to determine the distance of penetration, the device must effectively be destroyed to find the end point of the projectile's path. Similar to Jones, the device does not provide a means for remaining in place at impact. Moreover, it does not provide selectively removable inserts to discern penetration depth or any simulant for internal organs.
Thus, none of the previously described devices take into account all four of the heterogeneous materials that would be penetrated by a projectile for a shoulder-to-shoulder shot on a big game animal. What is needed, therefore, is a torso simulation device for projectile performance testing which includes mechanical analogs or simulants for all anatomical tissues. It should enable quick and easy discernment of penetration depth and wound cavity by using selectively removable inserts that can be replaced for each test. The device should permit the installation of varying inserts and materials to closely approximate the actual width and specific gravity of a wide range of animals, including deer, elk, bear, eland, buffalo, and other big game. The device should also be a stable platform capable of withstanding movement in response to the high energy impact of a projectile, such as a rifle bullet or arrow. Finally, it should be relatively compact, portable, and simple to maintain in consideration of the distances required for testing in potentially remote locations.